Of the several types of phytoestrogens, isoflavones (found mainly in legumes, particularly soya beans), lignans (found in wholegrains, flaxseed, berries and nuts) and coumoestans (found in forages, clovers and legumes) are used in supplements for women.
Resorclic acid lactones are sometimes referred to as phytoestrogens, but this is not strictly accurate. They are mycotoxins produced by soil dwelling moulds, and their presence in foods is the result of mouldy contamination of stored plant material.Isoflavones, lignans and coumoestans are known as phenolic phytoestrogens. Phenolics are members of the largest single family of plant substances known as flavonoids. Over 4000 different flavonoids have been identified.
Of all the phenolic phytoestrogens, the isoflavones (a family of over 1000 different substances) are the most widely studied.
A limited number of phytoestrogens, usually those with the greatest oestrogenic potential, are commonly used in supplements. The table below shows the most oestrogenic members of each of the phytoestrogens commonly used in supplements.
Isoflavones Lignans Coumoestans
Biochanin Matairesinol Coumoestrol